manifold vs telephone exchange

manifold

noun
  • A pipe fitting or similar device that connects multiple inputs or outputs. 

  • A copy made by the manifold writing process. 

  • The third stomach of a ruminant animal, an omasum. 

  • A polygon mesh representing the continuous, closed surface of a solid object 

  • A topological space that looks locally like the "ordinary" Euclidean space ℝⁿ and is Hausdorff. 

verb
  • To multiply or reproduce impressions of by a single operation. 

  • To make manifold; multiply. 

adv
  • Many times; repeatedly. 

adj
  • Many in number, numerous; multiple, multiplied. 

  • Various in kind or quality; diverse. 

  • Complicated. 

  • Exhibited at diverse times or in various ways. 

telephone exchange

noun
  • any equipment that establishes connections between telephones 

  • the rooms housing such equipment 

How often have the words manifold and telephone exchange occurred in a corpus of books? (source: Google Ngram Viewer )